I use a font (Aquiline), that has only a few characters, most notably the letter "A", which are quite huge in height.
I use LuaLaTex with the fontspec package.
So if I use this font and a capital A is in the line, the linespace is quite big compared to lines without that letter. It would be much nicer, if the linespace of the whole text would be the same. Preferrable even, if the line space would be like it is wihtout the presence of tha A and if this letter appears, it is no problem, if it intersects with the previous line.
But I have no Idea, how to achieve this.
\smash
is defined in plain tex, it should be available.\smash{A}
reduces the height (and depth) of its argument to zero, so it won't interact with adjacent lines.